We investigate the linear and nonlinear dispersion and absorption properties of a weak probe ¯eld in a slab doped with V-type atoms. The e®ect of relative phase between applied ¯elds on linear and nonlinear dispersion and absorption is discussed. It is demonstrated that the system is phase-sensitive when spontaneously generated coherence (SGC) exists. The e®ects of coupling ¯eld intensity, incoherent pump, and phase di®erence between probe and coupling ¯elds on Kerr nonlinearity are also presented.
